HEALTH experts are warning caterers not to use imported eggs from Spain.

For they have been identified as the source of salmonella outbreaks around Greater Manchester.

Hundreds of catering firms in the region are being contacted as part of the alert.

It follows four outbreaks of salmonella in Greater Manchester and Cheshire this year been linked to contaminated Spanish eggs.

The imported eggs are not subject to the same rigorous checks as those produced on farms in Britain. The North West Health Protection Agency (HPA) has teamed up with the Food Standards Agency (FSA) after a national outbreak team identified at least 2,000 people nationwide who contracted salmonella from Spanish eggs in the last two years.

Experts believe the true figure may be as high as 6,000.

Caterers, restaurants and hotels are targeted in the health warning because they are the largest users of imported Spanish eggs. These are not generally available in supermarkets, and householders should not be at risk.

Spain is the largest single exporter of eggs to England and Wales. They are popular with caterers because they are cheaper than British eggs.

But health watchdogs say Spain has not caught up with the UK regulations on salmonella, which include vaccinating chickens to protect against the disease.

Tests by the national outbreak team found Spanish eggs were five times more likely to have salmonella compared with UK-produced eggs. Prof Martyn Regan, the north west's lead epidemiologist, said: "We are asking the catering industry in the region to help us eliminate these random outbreaks of infection by choosing UK eggs, which are less likely to be infected with salmonella."

Environmental health bosses have already written to Warrington and Stockport caterers after several recent cases of the disease, which causes severe diarrhoea, abdominal pain, nausea and sometimes vomiting.